In a historic and widely expected verdict, a Norwegian court has declared mass killer Anders Behring Breivik sane and guilty of murdering 77 people during the country’s worst peacetime tragedy.

Judge Wenche Elizabeth Arntzen sentenced the self-confessed gunman to the maximum punishment of 21 years of permanent detention, and a minimum of 10, for “terrorist acts” during a combined car-bomb attack on government buildings and shooting rampage at a political youth summer camp last year.

Judge Arntzen announced the “unanimous” decision of the five-judge panel just minutes after a neatly coiffed and well-dressed Mr. Breivik swaggered into court smiling broadly.

He remained unemotional as victims and their families sobbed in court and held hands as the details behind the 77 killings, most of whom were teenagers, were read aloud by the judges, who were also visibly moved by recounting once again the brutality of the unprecedented attacks.

The guilty verdict comes as welcome relief to victims and their families, who have been looking for closure 13 months after the tragic event. Breivik signaled as recently as last night that he would not appeal if found sane.

Svein Holden, Oslo public prosecutor, declined to comment during a short court break if he would appeal the verdict. The prosecution has argued that Breivik should be sent to compulsory mental healthcare because there was doubt over Breivik’s sanity.

Sanity has been at the core of this paradoxical case after two conflicting forensic psychiatric reports came to opposite conclusions. The first forensic psychiatrist team found the 33-year-old Norwegian was suffering from paranoid schizophrenia, while the second concluded he was not psychotic.